Re: [PATCH] bus/pci: fix bus info memleak during PCI scan

[David Marchand <david.marchand@redhat.com>]

On Fri, Nov 18, 2022 at 2:36 PM Tomasz Zawadzki
<tomasz.zawadzki@intel.com> wrote:
>
> During pci_scan_one() for devices that were already registered
> the pci_common_set() is called to set some of the fields again.
>
> This resulted in bus_info allocation leaking, so this patch
> ensures they are always freed beforehand.
>
> Fixes: 8f4de2dba9b9 ("bus/pci: fill bus specific information")
>
> Signed-off-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
> ---
>  drivers/bus/pci/pci_common.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/bus/pci/pci_common.c b/drivers/bus/pci/pci_common.c
> index 9901c34f4e..9a866055e8 100644
> --- a/drivers/bus/pci/pci_common.c
> +++ b/drivers/bus/pci/pci_common.c
> @@ -114,6 +114,7 @@ pci_common_set(struct rte_pci_device *dev)
>                 /* Otherwise, it uses the internal, canonical form. */
>                 dev->device.name = dev->name;
>
> +       free(dev->bus_info);
>         if (asprintf(&dev->bus_info, "vendor_id=%"PRIx16", device_id=%"PRIx16,
>                         dev->id.vendor_id, dev->id.device_id) != -1)
>                 dev->device.bus_info = dev->bus_info;

Indeed, good catch.

The bus_info content is constant for a given device, there is no need
to free and reallocate.
WDYT of:

@@ -114,8 +114,9 @@ pci_common_set(struct rte_pci_device *dev)
                /* Otherwise, it uses the internal, canonical form. */
                dev->device.name = dev->name;

-       if (asprintf(&dev->bus_info, "vendor_id=%"PRIx16", device_id=%"PRIx16,
-                       dev->id.vendor_id, dev->id.device_id) != -1)
+       if (dev->bus_info != NULL ||
+                       asprintf(&dev->bus_info, "vendor_id=%"PRIx16",
device_id=%"PRIx16,
+                               dev->id.vendor_id, dev->id.device_id) != -1)
                dev->device.bus_info = dev->bus_info;
 }


-- 
David Marchand